DESCRIPTION: The types of patients which dentists perceive as "risky" are increasing. In addition to the "usual suspects," i.e., these infected with human immune deficiency virus (HIV) or hepatitis B virus (HBV), drug resistant tuberculosis is the latest infectious disease, in what may become a major rapidly emerging drug resistant infection disease problem, which dentists will perceive to be an important threat to their health and safety. Not surprisingly, avoidance of risky patients is not uncommon. Understanding this avoidance behavior is very important; because of it patients most in need of oral health care do not receive it. The most important long-term objective of the planned research is the specification, estimation and testing of a causal model which mirrors the process by which dentists make a decision to treat risky patients. Data will be supplied by a systematic random sample of eligible private general practice dentists in New York City. Creation of the final data collection instrument will be preceded first by in-depth interviews with 60 dentists from the target population, and second by pretests with another 60 dentists from the same population. The final questionnaire will be mailed to approximately 665 dentists with an anticipated yield, based on previous experience, of approximately 400 usable questionnaires, the number necessary for data analyses, per the investigators' power analysis. The endpoint, or outcome, of the model is the decision to treat, to be measured by actual behavior rather than self-report. The proposed model is consistent with the Theory of Planned Behavior (TPB). LISREL will be used to determine the best of a number of plausible models. Because this project includes a test of the utility of a well respected theory, in a completely new behavioral domain, the project will make a significant contribution to theory. At the same time, the findings are expected to provide a significant advance in understanding the phenomenon, i.e., the process by which dentists decide to treat or not to treat risky patients, a necessary precondition for designing interventions which ultimately lead to increased access to oral health care for these patients.